1. Field of the Invention
This invention relates in general to the field of automatic screw feeding machines and in particular to the field of escapement arrangement whereby fasteners are received from a track feeding arrangement and are delivered to a driver head of an automatic screw feeding machine.
2. Description of the Prior Art
An automatic screw feeding machine is the terminology which is commonly applied to a machine which arranges fasteners, such as screws, from a bulk, loose form into an arrangement whereby the fasteners are aligned and then individually delivered to a driver head. The driver head is then utilized to drive a single fastener within a pre-existing hole so as to fasten one component to another. The purpose of such machines is, of course, to speed up production by providing rapid fastening of two or more components. Since speed of production is the main objective of such machines, any portion of the machine which tends to jam or malfunction in any manner results in a work stoppage which is contrary to such main objective. Each operation performed upon a fastener which is being utilized within a machine, from its bulk supply disposition to its fastened disposition and at any point therebetween, must necessarily occur in a serial mode whereby one step follows the other. Any one step, therefore, if it is not accomplished properly, will cause a complete shutdown of the machine and production. In today's modern factories, any production shutdown due to a malfunctioning machine must be avoided at all reasonable costs.
Screws, or other similar fasteners, used in industry are generally mass produced. Mass production involves greater tolerances for a given characteristic of the fasteners such as the head height, head diameter, or shank diameter, as compared to corresponding individualized custom machining of such fasteners. Automatic screw feeding machines must accommodate such mass-produced fasteners. The greater tolerances of the mass produced fasteners thereby imposes relatively difficult, individualized tasks on automatic screw feeding machines.
One area where automatic screw feeding machines of the prior art experiences difficulty is in receiving the fasteners from a track arrangement and subsequently delivering a single fastener in the proper orientation to a port or duct where the fastener is then pneumatically driven to the driver head of an automatic screw feeding machine. Escapament mechanisms of the prior art are known such that a slide receives a fastener and moves the fastener laterally to a position over a flexible conduit. The slide may be actuated by a solenoid or an air cylinder. When the fastener is moved to the position over the flexible conduit, it may drop by a combination of gravity and vacuum from a fluid pressure source introduced downstream of the outlet from where the fasteners are directed to the escapement mechanism or the driver head mechanism.
While such escapement mechanism are known in the prior art, there exists a need to improve upon the operation of such apparatus. The geometric configuration of screw fasteners does not readily lend itself to the operations inherent in such escapement or delivery systems. Because the head of a fastener is larger than the shank diameter of the fastener, it is difficult for automatic apparatus to grasp some portion of the fastener and mechically move it along a route of travel to a delivery point downstream of the pickup point. During the travel of the fastener and while being retained by the grasping and moving mechanism, it is required that the fastener maintain a substantially precise, predetermined orientation. The differences in diameter between the shank and head of the screw serves to make such operation very difficult. And, since continuous nonjamming operation is a major objective of such apparatus, satisfactory prior art apparatus is not available.
Accordingly, new, different, and improved escapement apparatus is desired, which decreases the tendency for mass-produced fasteners to become misoriented and thereby jam while being removed from an appropriate track feeding arrangement and delivered to a port whereby fasteners may be pneumatically ducted to the driver head of an automatic screw feeding machine.
It is to be noted and especially recognized that there are other objects of the present invention which although not specifically stated but which objects will be obvious to those skilled in the art to which this invention pertains, are intended to be included within the scope of the present invention.